ASSESSMENT OF ANTIBACTERIAL ACTIVITY OF ENDODONTIC SEALERS BY A DIRECT-CONTACT TEST

It is recognized that endodontic success depends on bacterial eliminat ion from the root and root canal system. Antibacterial activity of end odontic sealers can improve the success rate of endodontic treatment, provided the physical properties are not compromised. The aim of this study was to evaluate the antimicrobial properties of two endodontic s ealers (AH26 and Endoflas) using a direct contact test (DCT) which was designed for this purpose. The DCT is based on measuring the effect o f close contact between test bacteria and the tested material on the k inetics of bacterial outgrowth using a temperature controlled micropla te spectrophotometer (THERMOmax). For comparison, the agar diffusion t est (ADT) was performed for both materials. The results of the DCT sho wed that Endoflas was a significantly more potent bacterial growth inh ibitor than AH26, whereas when assessed with the ADT, AH26 was capable of producing a larger inhibition zone than Endoflas. The DCT by being quantitative and virtually independent of solubility and diffusion, w as found more suitable to assay solid surfaces. The results demonstrat ed the added value of DCT in the study of the antimicrobial properties of endodontic sealers.